1. Field of the Invention
The present invention relates to a hybrid artificial wetland water purification system, and a sewage treatment device using the same, and a natural nonpoint purification device capable of simultaneously purifying river and lake water, and more particularly, to a low energy consumption-type multifunctional water quality purification system for a hybrid artificial wetland, and a sewage treatment device using the same, and a natural nonpoint purification device capable of simultaneously purifying river and lake water, wherein the invention can selectively or simultaneously treat nonpoint pollution sources, which leak out while raining, in an advanced manner when being applied to treat point pollution sources, such as sewage or waste water, or treating various pollutants that are contained in streams or lakes.
2. Description of the Related Art
In general, sources of water pollution are largely classified into point pollution sources and nonpoint pollution sources according to their prevention and management.
Point pollution sources refer to pollution sources that discharge contaminated water, such as sewage, factory wastewater, or livestock wastewater, in a specific position.
Nonpoint pollution sources are discharge sources that discharge water pollutants at unspecific locations, such as the ground, a road, a farmland, a mountain area, or a construction site. Pollutants contained in the water that originates from rainwater and passes through a cultivation land, a ranch, a metro area, a forest area, a parking lot, a road, various construction areas, factory and industrial regions or from water which permeates underground, are main examples of nonpoint pollution sources.
Until now, various technologies have been applied to purify point and nonpoint water pollution sources. Among the various technologies, artificial wetland water purification systems have advantageous economic effects with respect to construction and maintenance costs, allowing comparatively stable water purification systems. Furthermore, low energy consumption and convenient operation of these purification facilities, permits wider applicability of these water purification systems.
However, artificial wetland purification technologies according to the conventional art, use a vertical or horizontal flow of artificial wetland utilizing a single reactor tank. Therefore, it is difficult to treat high-concentration pollutants and eutrophication materials, such as nitrogen and phosphorus, with high efficiency, and treatment efficiency may vary greatly according to changes in flow rates or water quality, thereby limiting existing natural purification technologies.
Furthermore, in artificial wetland purification technology, a site area of generally 10 to 30 m2/m3·IL or more should be treated, depending on different types of pollution sources. As a result, this has been recognized as the largest disadvantage, in spite of the myriad advantages.
A mechanical, device-type, and facility-oriented treatment method has mainly been applied to the treatment of point pollution sources. This method employs highly trained professional manpower that resides on-site and requires continuous management. A technology that can replace this high energy and high consumption-type treatment method has been desired because the maintenance thereof is very difficult, and management costs are very high.
Therefore, high-concentration and high-efficiency inlet water treatment problems that cannot be solved by natural purification technologies need to be solved, and the development of natural-type purification technologies, whereby the treatment of nitrogen and phosphorous, which are the causes of eutrophication, is required.
Nonpoint pollution sources have the following characteristics: the generation of the pollutant is both artificial and natural, the pollutant discharge location is nonspecific, the pollutants are diluted, dispersed, and discharged over wide regions, and the prediction of the pollutant is difficult, the collection of the pollutant is difficult, treatment efficiencies are no uniform, and the design, application, and management of the current purification facilities are difficult.
These nonpoint pollution sources may be deposited into precipitation soils and sand that absorb most of the rainwater leakage and nutritive substances that cause eutrophication, such as nitrogen and phosphorous, oils, and heavy metals, which are critical to aquatic organisms in small amounts, organic substances, and poisonous substances, which are critical to aquatic organisms, such as agricultural pesticides, various bacteria, and viruses, and inert materials, all of which can be swept up and discarded as garbage at industrial sites. The frequency and discharge amount of these nonpoint pollution sources and materials greatly depends on the weather conditions, such as rain.
Meanwhile, methods of controlling nonpoint pollution sources according to the related art have been classified into physical methods, whereby various treatment facilities and structures are installed to control nonpoint pollution sources, and methods of applying nonphysical techniques, such as soil usage regulation, have also been used.
With respect to the physical methods mentioned above, there are permeation-types and device-types that require excess management, detention-types, such as free flow-type artificial wetlands and detention ponds wherein removal of the pollutants depends on the precipitation and detention, vegetation-types, such as vegetation filter strips or a vegetation waterways, sewage treatment-types, such as super high-speed agglomerating and precipitation facilities, and combined contact oxidation facilities which are installed at riverfronts or within rivers.
However, in each of the mentioned prior art examples, the initial investment costs are relatively high compared to nonpoint pollution source purification capabilities, and there may be difficulties associated with maintenance.
In addition, it may be difficult to apply the nonphysical techniques mentioned above because the purification efficiencies are low and there is the possibility of civil complaints.
Since treatment processes like the latter case are limited to physical treatment methods, such as precipitation or filtering, the performance of removing nonpoint pollutants, including nutrient salts including N and P, may be lowered.
Furthermore, the removal of suspensions, organic substances, and nutrient salts contained in the contaminated water depends on the filtering and absorption capabilities of the treatment plant. Thus, there may be limitations in maintaining the continuous performance according to different regions and seasonal times.
By using a simple filtering system employing an underwater medium layer consisting of gravel and rubble, management of the medium layer may be minimal or the performance of removing the nutrient salts may be low.
In the past, water purification policies for treating point pollution sources have been enforced in an effort to manage and reduce pollutants. However, as the standard of living is improved and the urbanization of more land increases, the impermeability of these regions increases, thereby changing the rain discharge characteristics, subsequently allowing large amounts of various pollutants to leak into the water system and cause lower water quality. Thus, a counterplan is required wherein nonpoint pollution sources, including rainwater discharge, need to be actively controlled to improve the water quality of rivers and lakes compromised by nonpoint pollution sources.
In particular, if nonpoint pollutants flow into surface or underground water, it is difficult to directly remove these pollutants, and since the costs for treating nonpoint pollution sources increase as the purification facility gets farther away from the pollution sources, the development of a purification system and a purification facility, both having excellent purification capabilities and being located where the nonpoint pollutants are generated, is urgently needed.
In addition, since the monitoring and operation of flow rates and water quality cannot be realized, problems associated with the management of the current purification facilities will arise, therefore, there is a need for new technologies for operating systems capable of easily managing and achieving effective operating objectives and low costs.
Furthermore, there is a need for the development of a purification system capable of purifying nonpoint contaminated water caused by rainwater. This new purification system also needs to be capable of purifying rivers or lakes. This system would be very useful for establishing clean water reservoirs, especially during drought seasons.